We analyse the behaviour of acoustic vortex beams interacting with rotating, fluid-saturated porous materials. Regions of the parameter space that exhibit distinct dynamical features are identified, with a focus on features that are relevant to the characterization of rotational superradiance. We discuss the similarities and differences between two recent proposals to observe acoustic superradiance with rotating, air-saturated sound absorbers. Finally, theoretical predictions for macroscopic acoustic scattering, obtained by averaging over interactions between the fluid and the porous material at the microscopic level, are compared with predictions of the first-Born approximation. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

中文翻译：

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声学超辐射的动态景观


我们分析了声涡流束与旋转的流体饱和多孔材料相互作用的行为。识别出表现出不同动力学特征的参数空间区域，重点关注与旋转超辐射表征相关的特征。我们讨论了最近两项利用旋转、空气饱和吸声器观察声超辐射的提议之间的异同。最后，通过对微观水平上流体和多孔材料之间的相互作用进行平均而获得的宏观声散射的理论预测与初生近似的预测进行了比较。本文是“下一代模拟重力实验”讨论会议问题的一部分。